Construction of internal-combustion-engine cylinders



' V. B. HARLEY- MASON CONSTRUCTION OF INTERNAL COMBUSTION ENGINECYLINDERS Feb. 19, 1924.-

Filed May 7; 1925 2 sheeis-sneeg f1 Patented F eb. 19, 1924.

UNITED VERNON pa rol-m HAnn-nY- mAsoN, or onE-Aivr, ENGLAND.

consrrwcrron or ritrnniwn;-ooilrnusrronarteries CYLINDERS.

Application filed may 7,

To all whom it may concern:

Be it known that I, VERNON Bnnroo'n HARLEY-MASON, a subject of the Kingof Great Britain, and a resident of Cheam, in the county of Surrey,England, have invented a certain new and useful Improvement in theConstruction of Internal-Combustion-Engine Cylinders, of which thefollowing is a specification.

This invention relates to the construction of the cylinders of internalcombustion engines. As is well known the stresses set up in internalcombustion cylinder walls are due to two main causes, viz., pressure ofthe working fluid within the cylinder and difference of temperaturewithin the thickness of the wall due to heat flowing from the hotinterior to the cooling medium outside.

Increases of fluid pressure within the cylinder can be met by increasingthe thickness of the cylinder wall but the limit to which thisthickening up can be accomplished in practice is soon reached for thereason that this increase of wall thickness, while it diminishes thestresses due to the fluid pressure, increases the heat stresses due totemperature difference. It will thus be seen that opposite conditionshave to be met and the ordinary practice is to make the cylinder wall asthick as possible having regard to the temperature conditions and thusthe diameter of the cylinders of internal combustion engines is limitedby the necessity for simultaneously accommodating these two conditions.In order to overcome this difliculty and increase the size to which thecylinders can be built it has been suggested to make the cylinderthin-so thin that it cannot resist the pressure stresses to which itwould be subjected in normal workingand support it from outside by somepressure resisting means. It is of course also well known to provide acylinder with ribs.

In an internal combustion engine cylinder, the intensity of the abovementioned stresses is not uniformly distributed throughout the length ofthe cylinder but is greatest at that part of the cylinder wherecombustion takes place and rapidly falls towards the end or ends remotefrom 'the combustion zone. That portion of the cylinder wall which isexposed to very high stresses is very short.

That is to say the part of an internal combustion engine cylinder whichis subjected to the extreme stresses due to pressure and 1923. Serialno. 637,306.

temperature is comparatively short in length and may be regarded as thatpart of the combustion space when the charge is at its maximumcompression. After the piston has moved a certain distance the pressurehence the stress due to pressure commences to fall and the heat stressesalso diminish toward the cylinder end or ends. Thus so far as the endor. ends of the cylinder remote from the combustion zone are concernedthe thickness of the walls can be increased without stresses.

- According to my present invention I form the cylinder thin at or aboutthat part where it is subjected to the higher stresses and I strengthenthis thin part by ribbing it in such a manner that the ribs aresupported at each end on thicker parts of the cylinder wall thesethicker parts adequately accommodating the fluid pressure stresses andalso in spite of the thickness being involving undue quite able towithstand the heat stresses which, as before indicated are muchdiminished at those parts.

Each of the ribs aforesaid constitutes a beam which may. be of anysuitable section and this section may vary throughout its length and thepreferred arrangement is to give these ribs a T headed section.

In engines of the opposed piston type, the highly stressed and heatedportion occurs at or near the middle of the length of the cylinder walland suilicient section of cylinder wall to afford the necessary supportis thus given on both sides of the highly stressed and heated portion.

In single piston engines however, especially in cases where a separatecylinder cover is fitted, the highly stressed and heated portion occursat one end of the cylinder barrel and it may be necessary to provideadditional supporting section on one side of the highly stressed andheated section.

This may be done in any suitable manner, such as, for instance,producing the wall for some distance and sinking the cover into it acorresponding amount or by turning it outwards in the form of a flangeor even by de-. signing the ribs to act as cantilevers instead of beams.

In the accompanying drawings I have illustrated embodiments of 'myinvention Fig. 1 being a longitudinal section of the combustion end of acylinder wall constructed in accordance with my invention,

Fig. 2 is a transverse section on the line 2-'2 of Fig. 1. Fig. 3'is alongitudinal section of a cylinder Wall for an engine of the opposedpiston type constructed in accordance With my invention and Figs. 4: and5 are fragmentary views illustrating some of the forms the ribs may takein section.

Referring to these drawings throughout which like numerals of referenceindicate corresponding parts the numeral 1 designates the cylinder Wallwhich is made thin by which is meant it is not sufficiently thick toWithstand the combustion pressures unaidedand this thinpart Which ofcourse, surrounds the combustion zone is strengthened by'means of ribs 2Which surround it,

' these ribs being anchored to thickened portions 3 and l of thecasting. If desirable these ribs may be further supported at or acent tothe pressure Zone by a reinforcing hoop 5 as indicated in Fig.3 of thedraw ings, in accordance with the principle outlined in British LettersPatent No. 1750 of 1912 granted to WVilliam Joseph Still.

As before mentioned the ribs 2 may be of any desired section and thesection may vary at different positions throughout their length and inFigs. 4 and 5 I have illustrated special sections Which may be adoptedthe T section shown in Fig. 2 being the form I regard as most suitablein general. 7 Y

Further these ribs may be arranged either parallel to the axis of thecylinder as shown or may be inclined at some suitable angle thereto.

What I claim ters Patent is V g l. A cylinder for internal combustionengines having that part of its Wall Which in the operation of theengine is subjected to the higher temperature and pressure stressesformed thin and strengthened by integral ribs connected to thicker partsof the cyl inder Wall. r

2. A'cylinder for internal combustion engines according to claim 1 andin Which the ribs are reinforced by a strengthening band encircling oradjacent to the pressure zone.

In Witness whereof I aiiiX my'signature.

VERNON BALFOUR HARLEY-MASON.

and desire to secure by Let- V

